Everything you need to know about growing and harvesting jamun! Learn about: 1. Botany of Jamun 2. Origin of Jamun 3. Climate and Soil 4. Orchard Cultural Practices 5. Propagation Techniques 6. Planting Operation 7. Flowering and Fruiting 8. Training and Pruning 9. Harvesting and Handling.
Botany of Jamun:
The genus Eugenia comprises about 1000 species of evergreen trees and shrubs, most of which are tropical in origin. Some of the old World Eugenia sp. are now placed in the genus Syzygium. It belongs to the family Myrtaceae. Many of the species yield edible fruits and some of these are of ornamental and medicinal value.
The large evergreen tree has small dark purple fruit with prominent elongated seed. The fruit is astringent even when ripe. A popular fruit is the rose-apple or gulab jamun (Syzygium jambos). It is found in South India and West Bengal, the tree is very ornamental. The fruit is yellow in colour, generally insipid in taste and has high pectin content. The species (Syzygium zeylanica) grows as a small tree with edible fruits, is found on the Western Ghats of India. A few trees of species Syzygium malaccense (Malay rose-apple) are found in South Africa. The species Syzygium densiflorum is used as rootstock in jamun and it is resistant against the attack of termites.
The tree of Syzygium cumini is 16-25 m high, branchlets white. Leaves are broadly oblong or oval, bluntish acuminate. The tree can live more than 100 years.
In jamun, new vegetative shoots emerge as terminal growth on the previous season’s branchlets. The new shoots in jamun emerge in two distinct flushes, i.e. from February to May and August to October. The growth of these shoots is completed in two phases i.e. from first week of March to second week of April and from second week of August to last week of October or second week of November.
The flush which appears in the month of February produces maximum growth and flowering. Flower bud differentiation has been observed on 5 to 10 month old branches and it started from last week of January and continued for 43 days. The floral parts arose in acropetal succession.
Origin of Jamun:
The Jamun (Jaman) or Java plum, syzygium cuminii (Eugenia jambolana), is considered to be native to India or farther east. It belongs to the family Myrtaceae to which also belong the guava. It is a common tree all over India, wherever the mango is found. It is not grown in regular plantations but is a common roadside tree. A related wild species, S. fruticosum, with small, but edible fruits is grown as a windbreak around orchards. Jaman fruits are a good source of iron used as an effective medicine against diabetes, heart and liver trouble.
The large evergreen tree has small dark purple date-like fruits with prominent elongated seeds. The colour of the flesh is also purple and the fruit is astringent even when ripe. Some superior types have large fruits with whitish flesh. The fruits ripen a little later in the season than mango. It is usually propagated from seed.
The seeds have no dormancy; hence fresh seeds need to be sown immediately. Patch and Forkert methods of budding are also successful and performed in March. The fruit is usually shaken with salt before eating. Two insect pests, the leaf-eating caterpillar (Carea subtilis) in South India and a white fly (Dialcurodes eugenia) in all parts of India are commonly found.
A similar fruit, which is more tropical, is the rose apple or gulab jaman (S, jambos). It is found in South India upto elevations of 1,200 metres. It grows in both dry and humid areas. Its leaves are larger and the tree is very ornamental. The fruit is of the size of a golf ball and greenish yellow in colour. The flesh is spongy and aromatic. The fruit does not have any commercial value, but can be used for candying, etc.
Another similar species, S. javanica, bears fruits profusely. It is propagated from seed, but layering is also possible. Other species of Syzygium found in India are S. kurzii, S. formosa found in the Eastern Himalayas, S. zeylanica, a small tree with edible fruits, found on the Western Ghats of India, and S. malacensis, a few trees of which are found in South India.
Another related fruit found in South India is the Surinam cherry, Brazil cherry or the pitanga (Eugenia uniflora). It is a small tree with bright red angular fruits less than 2.5 cm in diameter, having an aromatic flavour. It is seen in South India at elevations from 500 to 1,500 metres and can also grow in North India. The clove, Syzygium aromaticum, is also closely related to the above plants.
Climate and Soil Required for Growing Jamun:
Jamun is successfully grown under tropical and subtropical climate. It also occurs in the lower range of the Himalayas up to an elevation of 1300 metres and in the Kumaon hills upto 1600 metres above sea level. It is widely grown in the larger parts of India from the Indo- Gangetic plains in the North to Tamil Nadu in the South. It is one of the most hardy fruit crop and can be easily grown in neglected and marshy areas where other fruit plants cannot be grown successfully.
Jamun is somewhat more susceptible to cold and drought than the seedling mango trees. It requires dry weather at the time of flowering and fruiting. For ripening of fruit and proper development of its size, colour and taste, early rains are considered very beneficial. The fruits show remarkable improvement in these respects after the very first shower of rain. Jamun tree is exact in its soil requirements. The tree requires deep, loam and well-drained soil for its optimum growth and good fruiting. Its cultivation should be avoided in very heavy or light sandy soil.
Orchard Cultural Practices for Growing Jamun:
i. Irrigation:
During the initial year, the jamun plants required 8-10 irrigation in a year while bearing trees (full grown) required 4-6 irrigation during the summer months of May and June when fruits ripen. In the remaining period of the year, irrigation may be given when there are no rains or dry spell persists. During winter month, irrigation proves useful as it protects the plants from frost injury.
Jamun trees can thrive well under rainfed condition as it develop deep tap root system and able to extract water from the deeper layers of soil.
ii. Intercropping:
To supplement the income from pre-bearing period of jamun, intercropping should be practised judiciously. Intercropping also improved fertility of the soil. Fruit crops like, peach, plum, guava, kinnow, kagzi lime, phalsa, and papaya can be grown as filler trees. Such filler trees can be uprooted when the jamun trees starts bearing commercial crop. The leguminous crops like gram, peas, moong and mash can be grown successfully. In addition, intercrops of vegetables near established market may be taken with cauliflower, cabbage, knol khol, radish, brinjal, turnip, carrot etc.
iii. Manuring and Fertilization:
During the per-bearing period of jamun, a dose of 20 kg well rotten farmyard manure should be applied. To the bearing tree 80 kg FYM per tree should be supplied annually for proper growth and fruiting. Sometimes in highly fertile soils, the plants produce profuse vegetative growth and fruiting is delayed. Under such conditions, the manures should not be given and irrigation should also be given sparingly and withheld in September-October and again in February-March. This procedure will prove beneficial in fruit bud formation, flowering and fruit setting. Ringing and root pruning are also helpful.
The Jamun trees should be manured and fertilized judiciously for obtaining commercial crop. One year old plant can be given 5 kg FYM, 125 g nitrogen and 50 g each phosphorus and potash. Every year same quantity of fertilizers should be increased and stabilize the dose at the age of ten years when the tree is considered full grown. At this age and after that add 50 kg FYM, 1250 g nitrogen and 500 g phosphorus and potash to each plant for economic bearing.
Propagation Techniques for Jamun:
Though lot of jamun plantation is seen on road side or scattered plantation at farmer’s field, yet no single well established orchard is reported in North India. Also no systematic work has been done on its propagation.
The most common method of jamun propagation is by seed. Seedling plant bears fruit of variable size and quality. For improved and selected true-to-true, vegetative methods of propagation like inarching, air-layering, grafting and budding have been advocated.
i. Sexual Propagation:
Seed are sown fresh in flat nursery beds during July when this fruit ripens. Seeds of Jamun remain viable upto three months after extraction from the fruit. The seeds should be sown at a distance of 15 cm in rows which are 25-30 cm apart. The seedlings can also be raised in polyphone bags of 22.5 – 30 cm size. The bags should be filled with a mixture of soil and farmyard manure in equal proportion. To drain out the excess water the polythene bags should be pricked from all sides before filling the mixture. It has been seen that more than one seedlings come out from a single seed. These seedlings are separated in different bags when they are about two weeks old. The seedling becomes ready for transplanting after one year.
Plants grown from seed become transplantable during next spring season. But it is advisable to keep them in the nursery upto next rainy season which is the best time of its plantation.
ii. Vegetative Propagation:
a. T-Budding and Patch Budding:
According to the recent research conducted at Punjab Agricultural university has revealed that jamun can be best propagated through T-budding and as well as through patch budding. The seedling of jamun is used as a rootstock. The per cent success is higher in T-budding (70%) than patch budding (60%). The best time for budding in both the cases is either during February-March or during August-September. However, the success during August-September is higher.
b. Inarching:
The rootstock used for propagating jamun is the jamun seedlings. For raising the rootstock, seeds are collected from healthy, vigorously growing and high yielding jamun trees. Seedlings are raised either in bed or in pots singly. In the month of June-July one or two year old rootstocks are inarched with the matching thickness of scion. Rootstock is watered if necessary till the grafts are separated from the parent tree. The union will complete in a period of about six weeks.
c. Veneer Grafting:
Veneer grafting gives 31 per cent success when one year old seedlings are used as rootstock. The shoots are taken from spring flush and the method is employed in the month of July.
Planting Operation for Growing Jamun:
Jamun can be transplanted during spring (February-March) or during monsoon (August- September). However, the later season of planting is considered better because the plants easily get established during the rainy season. The plants are transplanted with earth ball and are given irrigation till they get established. The size of the pit should be 1 x 1 x 1 m and these should be filled with a mixture of surface soil, silt and well rotten farmyard manure.
The jamun is planted at the distance of 10-12 metres in square system, thus accommodates 105-75 plants per hectare. The grafted and budded plants can be spaced at 8m x 8m and seedling trees at 10m x 10m.
Flowering and Fruiting in Jamun Trees:
The flowering in jamun starts in the first week of March and continues up to the middle of April. The trees are in full bloom in the second week of April. The inflorescence in jamun is generally borne in the axils of leaves on branchlet. The flowers are hermaphrodite, light yellow in colour. The maximum anthesis and dehiscence were recorded between 10 A.M. and 12 Noon. The pollen fertility was higher in the beginning of the season. The maximum receptivity of stigma was observed one day after anthesis.
Jamun is a cross-pollinated fruit. The pollination is done by honeybees, house flies and wind. The maximum fruit set i.e. 32.6 – 36.0% was obtained when pollination was done one day after anthesis. Thereafter, a sharp decline was observed in fruit set.
Three distinct phases of fruit growth in jamun are recorded. During the first phase (15-52 days after fruit set), the rate of growth was slow. In the second phase (52-58 days after fruit set), the rate of development was quite rapid and the third and last phase (58-60 days after fruit set) comprised comparatively slow growth with little addition of the fruit weight. The length and diameter of fruit showed a continuous increase with advancement of maturity.
The colour of jamun fruit changed from dark green at fruit set to light reddish colour at partial ripening and dark or bright purple at full ripe stage. The fruit took 63 days for compete ripening from fruit set. The ripe jamun had 76 per cent edible portion and 3. 1: 1 pulp to seed ratio. TSS and sugars followed an increasing trend, while tannin content followed a decreasing trend during growth and development.
Training and Pruning of Jamun Plants:
Jamun plants should be trained according to the modified leader system. Regular pruning is not required in jamun plants. However, in later years, the dry twigs and crossed branches are removed. While training the plant, the framework of branches is allowed to develop above 60-100 cm from the ground level. The branches of the Jamun tree are brittle, thus wider crotch angles in scaffold branches should be developed for better frame work. Annual corrective priming is done after harvesting the fruits.
Top Working:
The jamun plants, on account of their tap root system, do not stand transplanting well unless the operation is performed at a fairly young stage. The raising of budded plants in the nursery takes at least 2 to 3 years from the time of sowing the seed to the time of transplanting the plants in their permanent places. During this period, the root system goes rather deep and is badly injured while removing the plants from the nursery. This generally results in a fairly high percentage of mortality of the plants after transplanting.
In order to avoid this, the seeds may be sown in situ or very young seedlings transplanted in their permanent places and when they get established in 2 to 3 years and give out 3 to 4 branches, the branches as well as the leader are budded in situ. The operation should be done in stages completing it in two years as otherwise if the branches and the leader are headed back in one stroke, the tree will receive shock and a set-back in growth.
Keeping of one or two ungrafted shoots or nurse shoots as they are called for a year or so, keeps the root system well fed and they also give protection to the scaffold limbs and the trunk from sun-burn and frost injury. The trunk and the exposed portion of scaffold limbs should be protected against sun burn by white-washing them with unhydrated lime and wrapping the exposed parts with old gunny bags or dry straw.
Harvesting and Handling of Jamun Fruits:
The grafted jamun starts bearing after 6-7 years while the seedling one after 8-10 years of planting. The fruit ripen in the month of June-July and takes about 90 – 120 days to ripen after fruit setting. The main characteristic of ripen fruit at full size is deep purple or black colour. The jamun fruit is non-climacteric in nature. The fruit should be picked immediately when it is ripe, because it cannot be retained on the tree in ripe stage. The ripe fruits are picked singly by hand and in all cases care should be taken to avoid all possible damage to fruits.
For harvesting, the picker climbs the tree with bags of cotton slung on the shoulder. The fruits of jamun is generally harvested daily and sent to market on the same day. The fruit is highly perishable and can be kept in good condition for about 2-3 days under ordinary conditions.
The average yield of fruit from a full grown seedling jamun tree is about 80-100 kg and from a grafted one 60-70 kg per year. The storage life of jamun fruit is 6 days at room temperature and 3 weeks at low temperature (9°C and RH 85-90%) when pre-cooled fruits are kept in perforated polythene bags.